the "frontline" documentary airs tonight on pbs. thank you so much for joining us this morning. >> thank you. >>> on to other news now $50 million worth of diamonds have been stolen in a daring overnight robbery of a belgium plane with passengers on board. eight masked thieves stormed the plane's cargohold and took the diamonds. the rough and polished stones were heading to switzerland and a senior international correspondent dan rivers explains investigators want to know if it was an inside job. >> reporter: we don't know for sure what level of collusion there was with the airport authorities but we're being told they cut a hole in the perimeter fence of the air field and simply drove on to the air field, pulled up right alongside the plane where this huge cache of diamonds were being loaded and held them up. they did it without firing a shot. they were said to be heavily armed and masked and made off with, the figure we've got according to the exchange rate is about $67 million worth of diamonds but that may go up because there's